60GHz unbound

I have to admit that a couple of years ago I was not a big fan of 60GHz wireless communication. The attenuation losses were so great and the design challenges so dicey that I figured UWB would easily beat it to market.

Even though 60GHz would theoretically deliver a higher data rate, UWB's promised 480 Mbits/s seemed good enough for most applications -- and it would get better over time. Or so I thought.

But then WiMedia stumbled. Suddenly the path to gigabit-per-second wireless wasn't so clear anymore. All eyes turned -- or should have turned -- to 60GHz.

But a complete front-end receive chain, phase-lock loop and power amplifier (PA) within a couple of years seemed like a bit of a stretch at the time.

I was wrong. At this week's ISSCC (International Solid State Circuits Conference) in San Francisco, IMEC: (1) unveiled pretty much of a complete solution; (2) predicted with some confidence that the first commercial 60GHz products would hit the streets in 2010, and (3) offered to share its secret sauce with companies who wish to join IMEC.

"We invite the industry to join our 60GHz research program and benefit from this knowledge as well as from IMEC's advanced heterogeneous integration technologies," said Rudy Lauwereins, vice president of IMEC's Smart Systems Technology Office.

The devices are fabricated in 45-nm technology. In case you are wondering (as I did), it is TSMC's plain vanilla digital CMOS process. No GaAs. Not even any RF extensions to the process. The design was created with standard Cadence tools. The antenna and antenna interface are IMEC proprietary.

If I were a UWB company that had been swamped in last year's rough surf (which was, in small part, created by some independent testing sponsored right here on WNDL) I'd be reaching for my phone right now.

IMEC does its technology transfer in part by conducting design classes for its corporate partners. The first commercial product, according to Lauwereins, might be something like a HDTV system that will transmit an uncompressed high-definition picture over 16 antenna paths over a 10 meter range using the HDMI protocol. Power consumption for the complete receiver will be a measly 1.6W. This is a true single-chip solution.

The innovations introduced at ISSCC consist of three technologies.

First, a digitally controlled receiver RF front-end in 45nm digital CMOS with a noise figure of only 6dB. It boasts a150x150-micron footprint and power consumption of 19mA at 1.1V supply voltage. Full-digital control makes it highly suitable for phased-array systems. Frequency can be tuned in the 57-66GHz range to accommodate available spectrum around world.

Second, a fully integrated 57-66GHz phase-lock loop (PLL) that outperforms all previous designs in terms of tuning range. I also delivers quadrature output phases at millimeter wave frequencies, which means it can be used in a zero-IF architecture. The circuit consumes 78mW at 1.1V supply voltage.

Third, a millimeter-wave power amplifier in 45nm digital CMOS with state-of-the-art output power and ESD protection. The push-pull power amplifier features a 1dB compression point of 11dBm between 50 and 67GHz at 1.1V supply voltage.